Pediatric health disparities in the area of asthma, obesity and cardiovascular fitness continue to exist. Specifically, asthma and obesity are highly prevalent co-morbid conditions that disproportionately affect ethnic minority and urban children. These conditions share pathophysiological (e.g., inflammatory mediators) and contextual (living in an urban neighborhood) correlates, which may increase the risk for both conditions. A key lifestyle behavior implicated in both asthma morbidity and obesity risk is physical activity. Some children with asthma tend to restrict overall activities, including physical activity, when symptoms are in poor control. Although stressors related to urban living may also serve as barriers to physical activity among this group, we know little about the potential cultural and contextual mechanisms that help explain the association between asthma and physical activity in ethnic minority children. This ancillary study offers a unique opportunity to examine the association between asthma, physical activity and cultural and contextual factors in a group of urban children who are followed as part of their participation in Project NAPS (Nocturnal Asthma and Performance in School (R01 HD057220; Koinis Mitchell, PI). Project NAPS includes three, 4-week assessment periods (Session 1, S2, & S3) over the course of one academic year. In this ancillary study, we will incorporate objectively measured physical activity, and perceptions of asthma, physical activity and context to the third assessment period (S3), and add a fourth assessment period (S4) to occur at the start of the following academic year. This additional time point will provide: 1) an opportunity to examine the co-occurrence of asthma and allergic rhinitis symptoms, physical activity, and sedentary behavior, and 2) an in depth examination (at S3 and S4) of potential cultural and contextual influences on physical activity in a sample of 150 children with persistent asthma who are overweight/obese or healthy weight. We hypothesize that children with more asthma and allergic rhinitis symptoms will participate in less moderate to vigorous physical activity (MVPA) and more sedentary activities. These associations will be more pronounced in children from Latino and AA backgrounds than in Non-Latino White children. We further hypothesize that fear related to asthma and perceptions of neighborhood safety will each be independent predictors of MVPA, and will predict activity levels beyond actual asthma symptom level and measured neighborhood characteristics. We also expect these associations will be more pronounced in caregivers from Latino and AA backgrounds. Finally, we hypothesize that caregivers' perception of exercise as a trigger for asthma will be related to less MVPA and more sedentary behavior. This association will be apparent even when accounting for children's actual exercise-induced brochospasm status (EIB). A similar pattern will be found for children's perceptions. This association will be more pronounced in caregivers and children of Latino and AA backgrounds. This line of research has significant implications for the development of cultural tailored interventions to: increase physical activity n urban children with persistent asthma; and improve caregiver understanding of asthma symptoms and exercise induced-bronchospasm. Ultimately, study findings could have implications for improving the standard of care for urban and ethnic minority children with persistent asthma.